by Rebecca Kessler Killer whales living off Antarctica have come up with an ingenious and deadly seal-hunting maneuver. After locating a seal loafing on an ice floe, groups of whales rush the floe, their tails pumping in sync to generate a wave that washes the seal into the water. If at first they don't succeed, the whales return relentlessly to deliver a barrage of waves—and they'll even reposition the ice floe or break it up to improve their odds of success. Once the hapless seal is in the water, the whales gang up to hunt it down, confusing it by blowing swarms of bubbles at it and dragging it below by its hind flippers until it's exhausted and drowns. Then, off they carry their catch to dismember it with remarkable precision and share it. Researchers from the National Oceanic and Atmospheric Administration's Southwest Fisheries Science Center in San Diego, California, describe 22 wave-washing attacks in Marine Mammal Science. Only five instances of wave-washing had previously been documented, and researchers had presumed it uncommon. But the new paper reports that wave-washing appears to be the main hunting tactic of a group of whales the authors call "pack ice killer whales"—and is probably unique to them. In fact, it may be a defining feature of this group. In a 2010 paper, the authors and colleaguesdescribed genetic evidence suggesting that there are at least three distinct species of killer whales rather than just one, as had been supposed. Pack ice killer whales belong to one of the proposed new species. These photographs show the pack ice killer whales' distinctive hunting behavior: how they spot a seal, how they wash it into the sea, and evidence of their extraordinary butchery. (Warning: Some images are graphic.) © 2010 American Association for the Advancement of Science.

Keyword: Evolution; Intelligence
Link ID: 15175 - Posted: 04.05.2011

By KAREN BARROW It is classified as a rare disease, but the chronic condition called Charcot-Marie-Tooth is one of the most common inherited nerve-related disorders, with an estimated 150,000 patients in the United States. It can be devastating to patients and their families, with crippling effects on balance and the ability to walk and grasp objects. Nor does it help that few people have heard of it, unless they are directly affected. “It’s like the hidden secret,” said Allison Moore, chief executive of the Hereditary Neuropathy Foundation, who has the disease. “And when you mention, ‘I have C.M.T.,’ people look at you like you have three heads.” The disease — named for Jean-Martin Charcot, Pierre Marie and Howard Henry Tooth, the researchers who first described it in 1886 — is actually a group of neurodegenerative conditions that gradually degrade the nerves in the feet, legs, arms and hands, usually starting in childhood. There is no medical treatment, though orthopedic braces and corrective surgery can help. © 2011 The New York Times Company

Keyword: Movement Disorders; Genes & Behavior
Link ID: 15174 - Posted: 04.05.2011

By TARA PARKER-POPE Meet Zach Anner, a 26-year-old filmmaker from Austin, Tex., who just won his own television show on Oprah Winfrey’s new network. He’s handsome, smart and funny — oh, and he gets around in a wheelchair. Mr. Anner has cerebral palsy, “the sexiest of the palsies,” as he puts it in his audition video. That line, along with a spoof of a failed TV show about yoga, has won him legions of online fans. (“This isn’t yoga,” he tells the camera as he writhes on the floor. “I’m just putting on pants.”) In an online contest for a spot on “Your Own Show” on OWN, the video received more than nine million votes — and not because of Mr. Anner’s disability, according to Lee Metzger, the show’s executive producer. “You do see the chair, and he has some erratic movements, ” Mr. Metzger said. “But once you start to talk to him, you see that his chair and his body are not what he’s all about. He’s a bright guy with a lot of great ideas, and he’s funny.” Cerebral palsy is caused by abnormalities in parts of the brain that control muscle movements. In mild cases, patients may have slurred speech and motor impairments; in severe ones, the symptoms include irregular posture, spasticity and inability to walk. Other performers have had cerebral palsy, among them RJ Mitte, who plays a teenager on the AMC series “Breaking Bad”; Josh Blue, who won the NBC reality show “Last Comic Standing” in 2006 with routines that mocked his own lack of motor control; and Geri Jewell, who had a recurring role on “The Facts of Life” in the 1980s. © 2011 The New York Times Company

Keyword: Development of the Brain; Movement Disorders
Link ID: 15173 - Posted: 04.05.2011

By ABIGAIL ZUGER, M.D. Does the reading public really need yet one more rundown of the repeatedly debunked claims linking childhood vaccinations and autism? The positions of those who uphold vaccine safety and those who assail it have at this point thoroughly saturated the news media; what more is there to say? Or so I thought before opening Seth Mnookin’s new book. Barely a dozen pages in, I began to reconsider, and by the end I had completely changed my mind: Mr. Mnookin’s passionate defense of vaccination may be just what the public needs, in equal parts because of what it says and because of who is saying it. Mr. Mnookin is no expert in the field — at least he wasn’t when he entered the fray. Neither a doctor nor a scientist, he has no vested interest in upholding the medical status quo (thus avoiding an accusation regularly flung at vaccine proponents). He hails instead from what might be called, sadly enough, exactly the opposite demographic: he is young and hip, got a good liberal arts education, lives in an upscale enclave and works in another, as a contributing editor of Vanity Fair. He is the father of a young child. And it is people of precisely this description who are slowly picking apart the safety net that protected their own childhoods, prompted by a well-intentioned mixture of arrogance, ignorance and confusion. It is not that these parents buy into some of the more lurid accusations out there, like the one floated by a British doctor that all pediatric vaccinations cause some degree of neurologic damage. It is more that the parents are alarmed by the hubbub and prefer to play it safe — but wind up defining “safe” in exactly the wrong way. In some communities nonvaccination rates have hit the double digits — well into the danger zone. © 2011 The New York Times Company

Keyword: Autism
Link ID: 15172 - Posted: 04.05.2011

By Laura Sanders SAN FRANCISCO — The next time you watch that guy on the dance floor do the robot to Mr. Roboto, his automatonic, jerky moves will speak to a surprising part of your brain: a region scientists thought was reserved for making sense of actions by others that you too are able to perform. New experiments challenge a common view of this “mirror system” by showing that it’s not just a copycat, but is able to respond to a much wider range of actions than what an observer can perform himself. This broadened capacity of the brain system may help explain how humans are able to quickly and effortlessly understand other people’s (and robot’s) actions, study coauthor Emily Cross of Radboud University Nijmegen in the Netherlands said April 2 in a presentation at the annual meeting of the Cognitive Neuroscience Society. “There are a lot of situations where you see actions that you can’t do with your own body,” Cross said. “If you think about watching a gymnast at the Olympics, watching a break dancer, or even watching Star Wars or Wall-E, we see all sorts of actions and agents that we can’t readily map onto our own motor systems.” To see just how the mirror systems responded to unnatural movements, Cross and her colleagues scanned the brains of 22 people as they watched a video of a man performing a natural, fluid dance or a machinelike robot dance. Researchers thought that parts of the mirror system, which includes parts of the parietal lobe at the top back of the head and the premotor cortex just in front of that, would show higher activation in an fMRI scan when the subjects watched the natural dance. Instead, parts of the mirror system showed a very strong signal when subjects watched the robot dance, a result that was “quite a surprise,” Cross said. © Society for Science & the Public 2000 - 2011

Keyword: Emotions
Link ID: 15171 - Posted: 04.05.2011

A new report from the drug company GlaxoSmithKline concludes that its antidepressant Paxil might make adults with major depression more likely to become suicidal. But the rate of suicide attempts was low, at 0.34 percent for people on Paxil and 0.05 percent for people who got sham treatment with a placebo pill in clinical trials. And it couldn't be entirely ruled out that the difference was due to chance, according to the report, published in the Journal of Clinical Psychiatry. "The scientific evidence does not establish that paroxetine" - the ingredient in Paxil -- "causes suicide, suicide attempts, self-harm or suicidal thinking," said Sarah Alspach, a spokeswoman for the drug company. "Nonetheless, all patients who are started on antidepressant therapy should be monitored appropriately and observed closely for clinical worsening, suicidality, or unusual changes in behavior." In general, antidepressants can be extremely helpful for people with depression. The American Academy of Family Physicians says on its web site, "Most people who have depression get better with treatment that includes these medicines." But the link between suicide risk and antidepressants has long been a thorny issue for regulators and drugmakers alike. The current data were initially published in 2006 on GlaxoSmithKline's website in response to widespread concern. SOURCE: http://bit.ly/hADiCH Journal of Clinical Psychiatry, online February 22, 2011. Copyright 2011 Thomson Reuters.

Keyword: Depression
Link ID: 15170 - Posted: 04.04.2011

by Andy Coghlan An ingenious set of experiments has teased apart the mind-altering and pain-relieving effects of the main component of cannabis. This could open the way to cannabis-like drugs that provide pain relief without causing unwanted highs. Cannabis is taken as a painkiller – to dull pain in cancer for example – but it can produce unpleasant side effects such as hallucinations and impaired mobility. Now, a team led by Li Zhang of the US National Institute on Alcohol Abuse and Alcoholism in Bethesda, Maryland, has shown that tetrahydrocannabinol (THC) – the active component in cannabis that makes people high but that is also thought to dull pain – binds to different molecular targets on cells to produce these two effects. It has long been known that THC gives people a high by binding to a molecular anchor on cells called the cannabinoid type-1 (CB1) receptor. Zhang and his team discovered that THC relieves pain by binding instead to receptors for the brain-signalling compound glycine and increasing their activity. Through experiments on mice, they then confirmed that if the glycine receptor is absent or if its activity is blocked by another drug, the animals experienced pain in a standard "tail-flick" test even when given THC, confirming that the drug's pain-relief and psychotropic effects can be decoupled. "We found that this glycine receptor could be a primary target for developing non-psychoactive forms of cannabis," says Lhang. © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch; Drug Abuse
Link ID: 15169 - Posted: 04.04.2011

By GINA KOLATA The two largest studies of Alzheimer’s disease have led to the discovery of no fewer than five genes that provide intriguing new clues to why the disease strikes and how it progresses. Researchers say the studies, which analyzed the genes of more than 50,000 people in the United States and Europe, leave little doubt that the five genes make the disease more likely in the elderly and have something important to reveal about the disease’s process. They may also lead to ways to delay its onset or slow its progress. “The level of evidence is very, very strong,” said Dr. Michael Boehnke, a professor of biostatistics at the University of Michigan and an outside adviser on the research. The two studies are being published Monday in the journal Nature Genetics. For years, there have been unproven but persistent hints that cholesterol and inflammation are part of the disease process. People with high cholesterol are more likely to get the disease. Strokes and head injuries, which make Alzheimer’s more likely, also cause brain inflammation. Now, some of the newly discovered genes appear to bolster this line of thought, because some are involved with cholesterol and others are linked to inflammation or the transport of molecules inside cells. The discoveries double the number of genes known to be involved in Alzheimer’s, to 10 from 5, giving scientists many new avenues to explore. One of the papers’ 155 authors, Dr. Richard Mayeux, chairman of neurology at Columbia University Medical Center, said the findings would “open up the field.” © 2011 The New York Times Company

Keyword: Alzheimers; Genes & Behavior
Link ID: 15168 - Posted: 04.04.2011

The brains of some aggressive and antisocial teenage boys look different than those of normal teenagers, British researchers have found. Conduct disorder is psychiatric condition characterized by higher than normal levels of aggressive and antisocial behaviour. It can develop in childhood or in adolescence and affects around five out of every 100 teenagers in the UK, researchers say. People affected by conduct disorder run a greater risk of further mental and physical health problems in adulthood. The new brain scan findings published in Friday's online issue of the American Journal of Psychiatry suggest adolescents who develop conduct disorder have differences in their brain and are not merely imitating misbehaving peers. "Changes in grey matter volume in these areas of the brain could explain why teenagers with conduct disorder have difficulties in recognizing emotions in others. Further studies are now needed to investigate whether these changes in brain structure are a cause or a consequence of the disorder," said Prof. Ian Goodyer of the University of Cambridge. For the study, scientists used MRIs to look at the brains of 65 teenage boys with conduct disorder and 27 healthy teenage boys.The volume of the insula, in yellow, was smallest in those with the most severe behaviour problems.The volume of the insula, in yellow, was smallest in those with the most severe behaviour problems. University of Cambridge © CBC 2011

Keyword: Aggression; Development of the Brain
Link ID: 15167 - Posted: 04.02.2011

By RONI CARYN RABIN Older lesbian, gay and bisexual adults in California are more likely to suffer from chronic physical and mental health problems than their heterosexual counterparts, a new analysis has found. They also are less likely to have live-in partners or adult children who can help care for them. The research brief was based on data from the California Health Interview Survey, the nation’s largest state health survey, gathered in 2003, 2005 and 2007 by the Center for Health Policy Research at the University of California, Los Angeles. Older gay and bisexual men — ages 50 to 70 — reported higher rates of high blood pressure, diabetes and physical disability than similar heterosexual men, according to the researchers. Older gay and bisexual men also were 45 percent more likely to report symptoms of psychological distress and 50 percent more likely to rate their health as fair or poor. In addition, one in five gay men in California was living with H.I.V. infection, the researchers found. Yet half of California’s older gay and bisexual men lived alone, compared with 13.4 percent of older heterosexual men. Older lesbian and bisexual women experienced similar rates of diabetes and hypertension compared with straight women of their age, but reported significantly more physical disabilities and psychological distress and were 26 percent more likely to say their health was fair or poor. © 2011 The New York Times Company

Keyword: Sexual Behavior; Stress
Link ID: 15166 - Posted: 04.02.2011

by Deborah Kotz I can completely understand how this babbling baby video went viral. There's really no way to watch it without smiling in wonder at whether they're having a meaningful conversation and contemplating how language develops even before words are learned. Children's Hospital Boston did a fabulous analysis of the science of babbling babies on its health blog. In the post, Hope Dickinson, coordinator of the Speech-Language Pathology Services at Children’s Hospital, says the babies -- who are twins -- are engaging in conversational babbling and even displaying turn tallking where one "speaks," pauses and lets the other respond. (I love how they find each other humorous.) The babies even use various intonations. "There is a fantastic rise and fall to their pitch and tones," says Dickinson in the blog post. Sentences end with emphasis, and sometimes end with an upward inflection as if asking a question. The babies also gesture with their hands, which grownups -- myself included -- do all the time. And they look like they're understanding each other. Dickinson says this sort of babbling is normal for babies who will eventually replace all the da-da-da-ing with words. These babies seem to already have a few. One says "mama," and the other repeatedly says "up" when lifting a foot. Parents should expect to hear their babies babble by around 8 to 10 months or so and should begin to hear a few words by 12 to 14 months, according to Dickinson. If these milestones aren't being reached, they should speak to their child's pediatrician. © 2011 NY Times Co

Keyword: Language; Development of the Brain
Link ID: 15165 - Posted: 04.02.2011

By Victoria Gill Old World monkeys have better numerical skills than previously thought, researchers have discovered. In a basic numeracy test, long-tailed macaques were able to work out which of two plates contained more raisins. Strangely, they only excelled in this test if they were not allowed to eat the raisins they were shown. The scientists report in the journal Nature Communications that the animals have the ability to understand the concept of relative quantities. The team of researchers from the German Primate Center in Goettingen initially tested the macaques by showing them two plates containing different numbers of raisins. When the animals spontaneously pointed to one of the plates, they were fed the raisins. But in this test, the monkeys often got it wrong - choosing the smaller amount. Lead researcher Vanessa Schmitt said that this was because, rather than thinking about quantities, the animals were thinking about how much they wanted to eat the raisins. "This impulsiveness impaired their judgement," Ms Schmitt told BBC News. BBC © MMXI

Keyword: Intelligence; Evolution
Link ID: 15164 - Posted: 04.02.2011

Alison Abbott There is no cure for the group of hereditary muscle-wasting diseases known as muscular dystrophy. That is particularly alarming because one of its commonest forms — type 1 myotonic dystrophy — becomes more serious as it passes down the generations, manifesting earlier and acquiring pernicious extra symptoms, such as delays to mental development. A group of French scientists have now unravelled molecular pathways that may be responsible for some symptoms of type 1 myotonic dystrophy. They used a controversial source of material: disease-specific human embryonic stem (hES) cell lines. They hope that their results, published online today in Cell Stem Cell1, will influence a French political debate that threatens to restrict such work. The French Senate will vote on the issue on 5 April, in the first reading of new legislation to update the country's bioethics law (see France mulls embryo research reform). Type 1 myotonic dystrophy results from a defect in just one gene — dystrophia myotonica-protein kinase (DMPK) — but that damage affects the expression of other healthy genes. The team of researchers, led by Cécile Martinat, a geneticist at the Institute for Stem Cell Therapy in Evry, identified two such genes that are suppressed in the disease. They showed that the suppression prevented neurons from efficiently building connections with muscle cells. Unlike in most genetic diseases, the damaged DMPK gene is not mutated. Instead, its code is interrupted by a long and unstable string of 'triplet repeats', in which three of the four nucleotides that make up DNA repeat themselves more than fifty times. The string of repeats tends to get longer with each generation. © 2011 Nature Publishing Group

Keyword: Movement Disorders; Stem Cells
Link ID: 15163 - Posted: 04.02.2011

by Helen Thomson Too much of it will make you go blind – or so you might have been told. But for some, masturbation might have a real clinical benefit: it can ease restless leg syndrome (RLS). The insight could provide sweet relief for the 7 to 10 per cent of people in the US and Europe who suffer from the condition. RLS is a distressing neurologic disorder characterised by an urge to move the legs. It is usually associated with unpleasant sensations in the lower limbs such as tingling, aching and itching. The exact causes of RSL have yet to be pinpointed, but brain autopsies and imaging studies suggest one contributing factor is an imbalance of dopamine – a hormonal messenger that, among other things, activates the areas of the brain responsible for pleasure. It is suspected that dopamine imbalance is responsible for some of the symptoms of Parkinson's disease. Drugs that increase dopamine have been shown to reduce symptoms of RLS when taken at bedtime and are considered the initial treatment of choice. Although such drugs provided significant improvement of symptoms for a 41-year-old man with RLS, he found an even better treatment – complete relief after masturbation or sex. Luis Marin and colleagues at the Federal University of São Paulo, Brazil, who report on the novel treatment this month in Sleep Science, speculate that the release of orgasm-related dopamine might play a role in the alleviation of symptoms. © Copyright Reed Business Information Ltd.

Keyword: Movement Disorders; Sexual Behavior
Link ID: 15162 - Posted: 04.02.2011

by Celeste Biever A SOFTWARE bot inspired by a popular theory of human consciousness takes the same time as humans to complete simple awareness tasks. Its creators say this feat means we are closer to understanding where consciousness comes from. It also raises the question of whether machines could ever have subjective experiences. The bot, called LIDA for Learning Intelligent Distribution Agent, is based on "global workspace theory". According to GWT, unconscious processing - the gathering and processing of sights and sounds, for example, is carried out by different, autonomous brain regions working in parallel. We only become conscious of information when it is deemed important enough to be "broadcast" to the global workspace, an assembly of connected neurons that span the brain. We experience this broadcast as consciousness, and it allows information to be shared across different brain regions and acted upon. Recently, several experiments using electrodes have pinpointed brain activity that might correspond to the conscious broadcast, although how exactly the theory translates into cognition and conscious experience still isn't clear. To investigate, Stan Franklin, of the University of Memphis in Tennessee, built LIDA - software that incorporates key features of GWT, fleshed out with ideas about how these processes are carried out to produce what he believes to be a reconstruction of cognition. Franklin based LIDA's processing on a hypothesis that consciousness is composed of a series of millisecond-long cycles, each one split into unconscious and conscious stages. In the first of these stages - unconscious perception - LIDA scans the environment and copies what she detects to her sensory memory. © Copyright Reed Business Information Ltd.

Keyword: Attention; Robotics
Link ID: 15161 - Posted: 04.02.2011

Catherine de Lange, reporter The star-shaped cogs in this video don't seem to fit together very well. The red cog jerks repeatedly as it rotates clockwise, and every time it aligns with the inner and outer blue cogs, the inner star jumps a bit in the opposite direction. But keep watching, and you'll see that all that jumping about was only in your mind's eye. The red star was rotating perfectly smoothly all along, while the inner blue star actually remained fixed throughout. This illusion was first discovered in 2006 by Peter van der Helm at the Radboud University Nijmegen, who's created a number of variations on the theme. But why does our brain insist that this shape is jumping? And what creates the illusion? Would it work differently if we changed, say, the colours? Let us know what you think in the comment thread below, and we'll reveal the answer next Friday. And here's the answer to last week's illusion. We came face-to-face with a deceptive snowman who fell to pieces as the camera angle changed. Why are we so quick to assume it's a whole snowman, rather than three ingeniously positioned snowballs? Our minds tend to work with patterns we are familiar with. In this case, working with the limited information provided by a single camera-angle view, we assume that three perfectly aligned snowballs must mean "snowman". (Similarly, yuo shd be abl to read ths sentnce evn thogh it cntains mstakes). © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 15160 - Posted: 04.02.2011

By Laura Sanders VANCOUVER — Great-grandfathers may impart more than engraved watches. A sugar-regulating gene that made a brief appearance in a lineage of mice but wasn’t passed on seems to have made animals up to four generations later resistant to obesity, research presented March 30 at the annual conference on Research in Computational Molecular Biology shows. “This changes the way we think about the inheritance of disease,” said study coauthor Joseph Nadeau of the Institute for Systems Biology in Seattle. The results may force researchers to grapple with complicated transgenerational gene influences. The surprising effect was caused by the single-generation appearance of a genetic variation that affects the maintenance of blood sugar, Nadeau and his colleagues reported. In the experiments, researchers allowed two inbred strains of mice to eat as many of the mouse equivalent of double cheeseburgers as they wanted. One type of mice grew obese on the diet and developed a suite of accompanying health problems, such as insulin resistance, high blood pressure and cardiovascular disease. The other type didn’t gain weight, even though these mice ate more than the first type and exercised less. By swapping a part of the skinny mouse’s DNA that includes the glucose-related gene into the obesity-prone mouse, the researchers could cause mice to stay slim on the high-fat diet. © Society for Science & the Public 2000 - 2011

Keyword: Obesity; Genes & Behavior
Link ID: 15159 - Posted: 04.02.2011

By KATE MURPHY In a culture where people cradle their cellphones next to their heads with the same constancy and affection that toddlers hold their security blankets, it was unsettling last month when a study published in The Journal of the American Medical Association indicated that doing so could alter brain activity. The report said it was unclear whether the changes in the brain — an increase in glucose metabolism after using the phone for less than an hour — had any negative health or behavioral effects. But it has many people wondering what they can do to protect themselves short of (gasp) using a landline. “Cellphones are fantastic and have done much to increase productivity,” said Dr. Nora Volkow, the lead investigator of the study and director of the National Institute of Drug Abuse at the National Institutes of Health. “I’d never tell people to stop using them entirely.” Yet, in light of her findings, she advises users to keep cellphones at a distance by putting them on speaker mode or using a wired headset whenever possible. The next best option is a wireless Bluetooth headset or earpiece, which emit radiation at far lower levels. If a headset isn’t feasible, holding your phone just slightly away from your ear can make a big difference; the intensity of radiation diminishes sharply with distance. “Every millimeter counts,” said Louis Slesin, editor of Microwave News, an online newsletter covering health and safety issues related to exposure to electromagnetic radiation. © 2011 The New York Times Company

Keyword: Miscellaneous
Link ID: 15158 - Posted: 03.31.2011

By Daniel Strain Wriggly roundworms (Caenorhabditis elegans), it seems, have found themselves a new philosopher’s stone. Doses of a dye used to visualize the proteins that build up in the brains of Alzheimer’s patients can up worm life span by more than half, California researchers report online March 30 in Nature. The dye, called thioflavin T, seems to prevent the deviant protein clumps often associated with a number of human age-related diseases, including Alzheimer’s, researchers say. During aging, the body accumulates proteins that aren’t shaped, or “folded,” the way they should be, says Richard Morimoto, a molecular biologist at Northwestern University in Evanston Ill. Like replacing finely tuned engine components with parts from a 30-year-old Yugo, those proteins don’t work and can even damage entire organs. “All of a sudden, your Porsche isn’t running like a Porsche,” Morimoto says. Misshapen proteins, for reasons that remain a hot topic of study, often sit in big clumps called aggregates. Such clumps have been spotted in any number of chronic illnesses from Alzheimer’s to Parkinson’s and Huntington’s disease. “The underpinning for all these diseases may be aging,” Morimoto says. Longer, healthier life may be possible, then, if doctors can keep misshapen proteins under wraps. That makes thioflavin T a potential protein mechanic. The California team fed the dye to roundworms genetically prone to getting debilitating clumps of protein in their muscles — the same kind of protein present in the brains of Alzheimer’s sufferers. Thioflavin T blocked many of those clumps from accumulating in the treated worms. Normal worms lived longer after eating the chemical, too. © Society for Science & the Public 2000 - 2011

Keyword: Alzheimers
Link ID: 15157 - Posted: 03.31.2011

by Sara Reardon If you want to know whether your new fluffy puppy will be a cuddly friend or snarl at and bite anything that moves, you might want to check out the length of its genes. Researchers at the University of Tokyo in Japan asked 100 Akita owners to fill out questionnaires about whether their pooches were naughty or nice. When they looked at the doggies' DNA, the scientists found that the meanest males more often had a shortened gene for a receptor that responds to various male hormones. The gene variant produces a form of the protein that has previously been shown to respond more strongly to testosterone. This is the first time that canine aggression has been associated with genetic differences in the male hormone receptor, the researchers report in Biology Letters this week. Over half of the Akitas they studied had this variant. Yet mean female dogs weren't more likely to have the short variant than the gentle dogs, suggesting that females respond differently to these hormones. © 2010 American Association for the Advancement of Science.

Keyword: Aggression; Hormones & Behavior
Link ID: 15156 - Posted: 03.31.2011